This invention relates generally to means for repairing pipeline leaks and, more particularly, to a leak repair clamp for sealing leaking flange pipe couplings, valve bonnet flanges, or leaks through the exterior of a pipe wall.
Flanged pipe couplings are widely used for connecting sections of pipe which operate in moderate to high pressures. Various configurations of seals are utilized between the flanges. One of the most common configurations is a raised face on the inner portion of each of the flanges with an annular gasket being placed between the raised faces. When the flanges are bolted together the raised faces compress the gasket material to form a seal.
Leaks often begin in such flange pipe couplings because of deterioration of the gasket material, shifting of the pipe and for other reasons. Similarly, a leak may occur in the outer wall of a pipe section due to a defect in the manufacture of the pipe or because of damage due to the pipe during or after installation. Such leaks must be repaired and often in the past the pipeline had to be shut down and drained of its contents before repair could be effected.
Pipe flange repair clamps for sealing the leak between pipe flanges are known in the prior art and some examples are those disclosed in U.S. Pat. Nos. 866,395 and 3,152,816 or in my U.S. pending patent application, Ser. No. 682,485. However, some of the pipe flange repair clamps are extremely complex and have a number of movable and adjustable parts that make the clamp expensive and difficult to utilize. Moreover, such pipe flange repair clamps normally embody an elastomeric material for centering the clamps around the pipe, pipe flanges and the like which also provide an initial sealing arrangement between the pipe and clamp. Such elastomeric seals are fine in most situations, but may be adversely affected in certain situations, such as when the leaking fluid is an acid or at a high temperature and pressure which effects the life of the material. To solve some of these problems, the elastomeric material can be specially selected, but this still does not solve the compression set properties of the material which leads to seal failure.
Accordingly, one of the primary objectives of the present invention is to provide a repair clamp for pipe and pipe flanges and the like which utilizes a self-energizing seal.
Another object of the present invention is to provide a leak repair clamp for pipe and pipe flanges and the like that centers the clamp around the pipe when connected thereto.
Another object of the present invention is to provide a leak repair clamp for pipe and pipe flanges and the like that receives a liquid sealant and directs the flow of the liquid sealant into contact with the pipe to thereby provide a self-energizing seal between the clamp and the pipe.
Another feature of the present invention is to provide a repair clamp for pipe and pipe flanges and the like that utilizes a lip which is an integral part of the clamp and formed to direct a liquid sealant into contact with the pipe.
Yet another feature of the present invention is to provide a simple clamp that can be utilized with minor modifications for sealing leaks in pipelines and pipeline sections and flanges.